CRM-20030 civicrm_api3 does not surface errors in chained API requests

The civicrm_api3() function which detects error conditions in the response object and converts them to exceptions, does not check the results of chained API requests, which may have nested errors preventing the parent request from completing.

Example response object wherein only a chained child request contains an error and is not detected and thrown by the civicrm_api3() wrapper:

{{
Array
(
[is_error] => 0
[version] => 3
[count] => 1
[id] => 35107
[values] => Array
(
[0] => Array
(
[id] => 35107
[contact_type] => Individual
[contact_sub_type] =>
... abbreviated for readability ...

[api.address.replace] => Array
(
[error_code] => 2000
[entity] => Address
[action] => create
[is_error] => 1
[error_message] => Input variable `params` is not an array
)

}}